docs: def _load(self, filename=None):
          """Read the SEVIRI rsr data"""
          if not filename:
              filename = self.seviri_path
  
          wb_ = open_workbook(filename)
  
          self.rsr = {}
          sheet_names = []
          for sheet in wb_.sheets():
              if sheet.name in ['Info', 'Requirements']:
                  continue
              ch_name = sheet.name.strip()
              sheet_names.append(sheet.name.strip())
  
              self.rsr[ch_name] = {'wavelength': None,
                                   'Meteosat-8': None,
                                   'Meteosat-9': None,
                                   'Meteosat-10': None,
                                   'Meteosat-11': None}
  
              if ch_name.startswith('HRV'):
                  wvl = np.array(
                      sheet.col_values(0, start_rowx=37, end_rowx=137))
                  # TODO: Add the 'extended' responses as well!
                  met8 = np.array(
                      sheet.col_values(1, start_rowx=37, end_rowx=137))
                  met9 = np.array(
                      sheet.col_values(3, start_rowx=37, end_rowx=137))
                  met10 = np.array(
                      sheet.col_values(5, start_rowx=37, end_rowx=137))
                  met11 = np.array(
                      sheet.col_values(6, start_rowx=37, end_rowx=137))
                  self.rsr[ch_name]['Meteosat-8'] = met8
                  self.rsr[ch_name]['Meteosat-9'] = met9
                  self.rsr[ch_name]['Meteosat-10'] = met10
                  self.rsr[ch_name]['Meteosat-11'] = met11
              elif ch_name.startswith('IR'):
                  wvl = np.array(
                      sheet.col_values(0, start_rowx=13, end_rowx=113))
                  met8_95 = np.array(
                      sheet.col_values(1, start_rowx=13, end_rowx=113))
                  met9_95 = np.array(
                      sheet.col_values(3, start_rowx=13, end_rowx=113))
                  met10_95 = np.array(
                      sheet.col_values(5, start_rowx=13, end_rowx=113))
                  met11_95 = np.array(
                      sheet.col_values(7, start_rowx=13, end_rowx=113))
                  met8_85 = np.array(
                      sheet.col_values(2, start_rowx=13, end_rowx=113))
                  met9_85 = np.array(
                      sheet.col_values(4, start_rowx=13, end_rowx=113))
                  met10_85 = np.array(
                      sheet.col_values(6, start_rowx=13, end_rowx=113))
                  met11_85 = np.array(
                      sheet.col_values(8, start_rowx=13, end_rowx=113))
                  self.rsr[ch_name]['Meteosat-8'] = {'95': met8_95,
                                                     '85': met8_85}
                  self.rsr[ch_name]['Meteosat-9'] = {'95': met9_95,
                                                     '85': met9_85}
                  self.rsr[ch_name]['Meteosat-10'] = {'95': met10_95,
                                                      '85': met10_85}
                  self.rsr[ch_name]['Meteosat-11'] = {'95': met11_95,
                                                      '85': met11_85}
              else:
                  wvl = np.array(
                      sheet.col_values(0, start_rowx=12, end_rowx=112))
                  met8 = np.array(
                      sheet.col_values(1, start_rowx=12, end_rowx=112))
                  met9 = np.array(
                      sheet.col_values(2, start_rowx=12, end_rowx=112))
                  met10 = np.array(
                      sheet.col_values(3, start_rowx=12, end_rowx=112))
                  met11 = np.array(
                      sheet.col_values(4, start_rowx=12, end_rowx=112))
                  self.rsr[ch_name]['Meteosat-8'] = met8
                  self.rsr[ch_name]['Meteosat-9'] = met9
                  self.rsr[ch_name]['Meteosat-10'] = met10
                  self.rsr[ch_name]['Meteosat-11'] = met11
  
              self.rsr[ch_name]['wavelength'] = wvl